Very peculiar electrical malfunction
 

Hi all, new forum member here. My husband has a 2006 CLK-350 which has developed a very strange disease, and I am hoping someone here will recognize the symptoms.

The first time it happened, we were driving down the freeway and the radio turned off. We turned it back on and all was fine. But a few minutes later the windows started to fog up and we realized the climate control was off. And a few minutes after that, the entire control panel, speedometer and such, went off. We pulled into a rest stop and he stopped and restarted the car, which brought everything back to life.

The next time it happened we were almost to our destination so he kept going; more and more things stopped working until finally the engine died, fortunately while we were in the parking lot. Once again, restarting the car fixed everything.

At this point he took it to the Mercedes dealer that does his regular service. They spent hours working on it but could not figure out what was going on; there were many codes being thrown but they couldn't determine which one represented the cause.

After getting it back he continued to drive it. Some days it would be just fine. Other days the climate control would keep going off, and he would have to keep stopping and restarting before the rot spread. Until the day he called me to come get him, because he had pulled over to restart and the car would not start....

He has an electronic key fob, and there was now a red blinking light on the key, a new development. I brought him the spare fob and with this he was able to start the car again. It has mostly sat in our garage since then while we figure out what to do next.

It's possible that the fob is failing and has done damage to the car's electronics. It's also possible that the car's electronics are failing and have done damage to the fob. Or that the two are unrelated issues.

Does this ring a bell with anyone? He already spent hundreds of dollars at the dealer with no resolution, and he has been told that the replacement fobs are obscenely expensive, so he doesn't really want to go back again without some idea of what might be wrong to help them focus their efforts.